Senior Software Engineer

[ABOUT ISTARI DIGITAL] Istari is a digital engineering software company enabling our customers to turn the physical world into the digital to accomplish their specific mission or business objectives. Istari was founded with the vision of making open, scalable digital engineering ecosystems a reality – where new technologies and systems are created digitally, free from the real-world constraints of costs and schedules. We are creating the world’s best engineering model sharing platform, allowing our customers to simply and securely integrate their models across different engineering disciplines, organizations, and security levels. At Istari, we are passionate about our mission of creating the world's first open and scalable industrial metaverse. Whether our customers are designing prototypes, performing virtual testing, or training AI and autonomy for complex systems, we know that going digital will save them time, resources, and reduce their environmental impact.   While we are a distributed team with most team-members working remotely, we place an emphasis on staying connected and collaborative, prioritizing in-person opportunities to build trust as a team. At Istari, we still believe that trust is best built in-person. To do this, we have an engineering headquarters in Cambridge, MA for focused technical development and several times per year we gather for an off-site that allows us to develop our professional skills and our team relationships. [VALUES] At Istari, we live by our values, which include: - Focus is rewarded. Finish is remembered.  - Facts are friendly. Even when they are not fun. - Fellowship is fundamental. Make others successful. Equal Opportunity Istari is an Equal Opportunity/Affirmative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity, national origin, age, protected veteran status, or disability status. We are seeking a highly experienced Senior Software Engineer to join our Core Platform team. In this role, you will own and evolve the end-to-end architecture of the Core Platform, including backend services, SDKs, AI-enabled capabilities, and supporting infrastructure. You will design and operate scalable APIs, event-driven systems, distributed services, and AI-integrated workflows, ensuring high standards for reliability, performance, observability, and security. This role requires strong architectural judgment, hands-on technical leadership, and the ability to collaborate cross-functionally to deliver extensible platform capabilities that support both traditional integrations and AI-driven use cases. You will help set technical direction, mentor engineers, and drive engineering best practices across the team. Key Responsibilities

Own the end-to-end architecture of the Core Platform, including backend services, SDKs, AI-enabled components, and related infrastructure.

Design and implement scalable APIs, event-driven systems, distributed services, and AI-integrated capabilities (including AI/ML and MCP integrations).

Architect systems that reliably incorporate AI models into production environments, with strong attention to observability, latency, cost management, and failure handling.

Lead API design and implementation with a focus on usability, performance, and long-term maintainability.

Architect and evolve microservices using domain-driven design principles.

Build platform abstractions and primitives that enable AI-driven workflows and agent-based capabilities.

Partner closely with Product, Infra, and Customer Success teams to deliver seamless, customer-centric integration capabilities.

Provide technical leadership, mentorship, and architectural guidance to engineers.

Establish and elevate engineering best practices across design, development, testing, and operations.

Required Qualifications

5+ years of professional software engineering experience, with at least 2 years in senior roles.

Proven experience building scalable, reliable, and secure distributed systems, including systems that integrate AI/ML capabilities.

Experience integrating AI-powered features into production systems, with an understanding of performance, reliability, and governance considerations.

Deep expertise in REST API design and implementation.

Experience designing and operating event-driven architectures.

Strong coding skills across multiple layers of the stack (backend services, SDKs, developer tooling, and AI-integrated systems).

Strong understanding of microservices architecture and domain-driven design.

Strong proficiency in Python (object-oriented and functional programming).

Experience with Golang and TypeScript.

Track record of technical leadership, mentorship, and cross-functional collaboration.

Excellent communication skills with the ability to influence at both technical and strategic levels.

Must be a US citizen living within the United States.